Increase in the production of allelopathic substances by Prymnesium parvum cells grown under N- or P-deficient conditions

Granéli, Edna; Johansson, Niclas

doi:10.1016/s1568-9883(03)00006-4

Cited by 185 publications

(164 citation statements)

References 29 publications

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“…baltica and various concentrations of Prymnesium parvum (P) cells grown under nitrogen-deficient, nutrient-sufficient or phosphorus-deficient conditions. Pure algal medium was used as starvation control Granéli & Johansson (2003) have shown that addition of P. parvum filtrates from cultures which had grown under N-or P-deficient conditions contained toxic substances able to kill several phytoplankton species. There was a clear difference in the degree of growth inhibition of the ciliate, whether nutrient-limited or nutrient-sufficient P. parvum cultures were offered as prey, suggesting that the survival of the ciliate in the presence of toxic P. parvum cells was strongly influenced by the physiological status of the P. parvum cells.…”

Section: Discussionmentioning

confidence: 99%

“…However, recent studies by Igarashi et al (1998), have shown that the haemolytic activity of prymnesins are not affected by Ca 2 but by the origen of the blood cell being tested. Several studies have shown that Prymnesium toxins damage cell membranes and exert lytic effects on various cell types including blood cells, human liver cells and amnion cells (Shilo & Rosenberger 1960, Meldahl & Fonnum 1993, Johansson & Granéli 1999, Granéli & Johansson 2003). Although we did not see the ciliate cells lyse, it is possible that P. parvum toxins have a similar mode of action on ciliates.…”

Section: Discussionmentioning

confidence: 99%

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Effects of the toxic haptophyte Prymnesium parvum on the survival and feeding of a ciliate: the influence of different nutrient conditions

Granéli¹,

Johansson²

2003

Mar. Ecol. Prog. Ser.

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We studied the growth and feeding response of the ciliate Euplotes affinis when exposed to algal cultures of Prymnesium parvum and Rhodomonas cf. baltica as monocultures or as mixtures. Cultures of P. parvum grown under nutrient-limited (N or P) or nutrient-sufficient conditions were tested for toxicity against E. affinis. Ciliates grew well when fed R. cf. baltica, but avoided grazing on monocultures of P. parvum, regardless of algal concentration. Increasing abundances of P. parvum decreased survival of the ciliate, even if supplied as a mixture together with high concentrations of R. cf. baltica as an alternative prey. This implies that P. parvum produces substances that were fatal to the ciliate when released to the medium. The lethal effect of P. parvum was dependent on the physiological status of the cells, with the highest toxicity in nutrient-stressed cultures. Our results suggest that toxin production in P. parvum may be a chemical defense to repel predators.

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Section: Discussionmentioning

confidence: 99%

Section: Discussionmentioning

confidence: 99%

Effects of the toxic haptophyte Prymnesium parvum on the survival and feeding of a ciliate: the influence of different nutrient conditions

Granéli¹,

Johansson²

2003

Mar. Ecol. Prog. Ser.

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“…Many studies focussed on phytoplankton defence mechanisms and protist prey selection (Wolfe 2000, Granéli & Johansson 2003, Strom et al 2003, Tillmann 2004, Roberts et al 2011). The present study on Uronema marinum adds a new dimension to predator-prey interactions, where chemical compounds have an effect on co-occurring species that are not directly preyed upon or are direct competitors.…”

Section: Discussionmentioning

confidence: 99%

Phytoplankton growth inhibited by the toxic and bacterivorous ciliate Uronema marinum (Protozoa, Ciliophora)

Schaafsma¹,

Peperzak²

2013

Mar. Ecol. Prog. Ser.

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The ubiquitous marine ciliate Uronema marinum is mainly bacterivorous. It was therefore surprising that in a ciliate-contaminated experiment the growth rate of the phytoplankton species Emiliania huxleyi was significantly reduced. As U. marinum does not ingest E. huxleyi cells, their growth inhibition was probably caused by a toxin secreted by the ciliate, presumably a novel type of chemical interaction between ciliates and phytoplankton. A possible function of toxin secretion is to lyse algal cells that are too large for U. marinum to ingest, to increase dissolved organic matter (DOM) concentrations and hence the growth of heterotrophic bacteria, the main food source of U. marinum. To test this hypothesis U. marinum or the filtrate of U. marinum cultures was added to cultures of phytoplankton with different cell sizes. The presence of U. marinum or the filtrate of U. marinum cultures showed an inhibiting growth effect and a negative effect on the physiology of all species tested although both effects were variable between species. Diatoms appeared less sensitive than non-diatom species. U. marinum acclimatization to phytoplankton led to stronger inhibiting effects, presumably from increased toxin production. Bacterial DGGE analysis of U. marinum cultures did not reveal known toxic bacteria that might account for the observed negative effects on the phytoplankton. Bacterial growth rates in an E. huxleyi culture increased when U. marinum filtrate had been added. In mixed cultures of bacteria, E. huxleyi and U. marinum, bacterial abundance first increased, then decreased due to ciliate predation. These findings support the hypothesis that toxin secretion by U. marinum increases non-prey phytoplankton-derived DOM and stimulates the growth of the bacterial prey.KEY WORDS: Uro ne ma marinum · Toxin · Phytoplankton · Bacteria · Growth rate · Physiology · Flow cytometry · FDA · Epifluorescence microscopy Resale or republication not permitted without written consent of the publisherMar Ecol Prog Ser 475: [35][36][37][38][39][40][41][42][43][44][45][46][47][48] 2013 even grow (albeit slowly) in water with a salinity <10 g kg −1 (Hamilton & Preslan 1969). Uronema spp. can be found residing in sediments and are abundant in coastal waters (Anderson et al. 2009). They are free-living ciliates and can be fast swimmers (Pan et al. 2010). Variations in U. marinum growth under similar culture conditions can be ex plained as genetic variability within species as a result of habitat or geographical isolation (Pérez-Uz 1995). The highest growth rates of U. marinum (0.25 ± 0.03 h −1 ) were found in isolates from an estuarine environment (Pérez-Uz 1995).Uro ne ma marinum is mainly bacterivorous and can easily be cultured on bacteria. Bacterial genera known to be utilized by U. marinum are Chromobacterium, Ser ra tia, Vibrio, Pseudomonas and Micrococcus (Plunket & Hidu 1978). U. marinum can feed on small phytoplankton as well (Rubin & Lee 1976). Strom & Morello (1998) cultured U. marinum on relatively small phytoplankton...

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“…Nevertheless, the uncoupling between intra-and extracellular toxicity during the different growth phases indicates an active release of the toxins. N and/or P depletion is a factor increasing toxicity in P. parvum (Granéli & Johansson 2003, Uronen et al 2005. In Trial 1, although the nutrients in the culture medium were adjusted to the Redfield ratio, the intracellular C:N:P ratio was lower during exponential growth at both salinities, indicating that P. parvum cells were likely P limited during stationary and senescent growth.…”

Section: Intra-and Extracellular Toxicitymentioning

confidence: 99%

“…Production of toxins may be the key mechanism by which Prymnesium parvum gains a selective advantage over other phytoplankton (Fistarol et al 2003, Granéli & Johansson 2003, and lower salinity might be a stress factor increasing toxin production in P. parvum (Reigosa et al 1999, Granéli et al 2012). Baker at al.…”

Section: Introductionmentioning

confidence: 99%

Effect of different salinities on growth and intra- and extracellular toxicity of four strains of the haptophyte Prymnesium parvum

Weißbach¹,

Legrand²

2012

Aquat. Microb. Ecol.

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The present study investigates the effect of brackish (7 PSU) and marine (26 PSU) salinity on physiological parameters and intra-and extracellular toxicity in 4 strains of Prymnesium parvum Carter. The different P. parvum strains were grown in batch cultures in 2 trials under different experimental conditions to test the development of intra-and extracellular toxicity during growth. The response of P. parvum toxicity to salinity was validated using 2 protocols. Intraspecific variations in growth rate, maximal cell density (yield) and cell morphology were controlled by salinity. Extracellular toxicity was higher at 7 PSU in all strains, but no correlation was found between intra-and extracellular toxicity. The variation of extracellular toxicity in response to salinity was much greater than that of intracellular toxicity, which indicates that P. parvum may be producing a variety of substances contributing to its various types of 'toxicity'.

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Increase in the production of allelopathic substances by Prymnesium parvum cells grown under N- or P-deficient conditions

Cited by 185 publications

References 29 publications

Effects of the toxic haptophyte Prymnesium parvum on the survival and feeding of a ciliate: the influence of different nutrient conditions

Effects of the toxic haptophyte Prymnesium parvum on the survival and feeding of a ciliate: the influence of different nutrient conditions

Phytoplankton growth inhibited by the toxic and bacterivorous ciliate Uronema marinum (Protozoa, Ciliophora)

Effect of different salinities on growth and intra- and extracellular toxicity of four strains of the haptophyte Prymnesium parvum

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